Cooking Is Simple, Like Chemistry, Right?
by Ennui Enigma
Summary: A very silly story that originally began with a prompt from laureleaf. Sherlock cooking? What could possibly go wrong! Now with chapters 2 & 3, whereby Mycroft seeks his revenge.
1. Chapter 1

**A/N: A couple of my readers might recognize some recent conversations in this story. Credit for initiating this piece goes to laureleaf who requested a humorous piece that included cake, cooking, and Mycroft. The toenail bit… well, one of you knows where that came from! Enjoy. Reviews always appreciated.**

**Disclaimer: Don't own or profit. Not beta'd. Potentially off-putting to a particular food. Very silly.**

* * *

"Did Mrs H bake us a cheesecake this afternoon, Sherlock?" The hungry doctor studied the dessert situated serenely on the kitchen counter, gloriously at least nine inches away from any of his partner's experiments.

"No, I baked it."

John looked again at the cake. "No, really, Sherlock. Where did it come from?"

"I made it this afternoon. I was bored." Graham cracker crumbs decorated the mans' dressing gown sleeves like gunshot residue and did seem to collaborate his statement.

John rolled his eyes. "Ha, ha…Sherlock. Now, seriously, who brought it over?"

The dark-haired figure on the sofa closed his eyes and folded his hands. "Clearly, John, we have reached an impasse in our communication tonight. Have the crying toddlers at the surgery finally sent you over the edge?"

"Sherrrrlooock…, you know what I mean. Are you seriously wanting me to believe that you, the man who can't even warm up leftover Chinese takeout, has succeeded in making a cheesecake?"

"John," his flatmate replied in a most irritating and annoying patient manner, "it's not as hard as you might think. I just followed the recipe and pretended I was mixing reagents and heating them like I do in my chemistry experiments. Simple, really."

John sighed. Then he sighed again when he realised how often he'd cooked meals while his flatmate could conceivably have shared in the culinary duties. He put the kettle on and brewed a couple cups while he considered the whole matter.

After a considerable silence, a soft rustle came from the sofa as the detective roused himself. "Um, John, in light of full disclosure, I must state that Mrs H did give me the crust, one of those pre-made things you buy in the supermarket."

John eyed the cheesecake's golden crust again. "Still looks delicious, Sherlock. Did you really just follow the recipe?"

"Yes."

John rose and went to get a serving utensil to divvy out the dessert.

"Um, John?"

"Yes, Sherlock?" John paused in mid-stride.

"I did make a few substitutions."

"A few substitutions... Precisely, what kind of substitutions?" John's put the knife back and bent over to sniff the dessert.

"We didn't have any gelatine. Luckily, with my knowledge of organic chemistry and a few spare appendages from my toenail experiments, I was able to concoct a gelatinous substitute."

John grimaced.

"Oh, don't be so narrow-minded. Everything was thoroughly boiled and completely sterile. It's not like I put poison in the cake!"

"Appendages and toenails…?" John couldn't get the image out of his mind.

"Don't be an idiot. Not the entire toe. Just the phalanges and the keratin-rich nails."

"Oh, so much better," John muttered under his breath.

"John, I'm ashamed of you. You should be proud of my accomplishment this afternoon. I realise it was a 'no-bake' recipe but still, it took skill to mix the ingredients in the proper proportions and simmer everything together until the desired consistency was achieved." His lower lip pouted and he gazed back at John with liquid blue eyes looking deeply injured.

"Ok. Fine. I'm glad you at least used your talents to make a cake rather than shoot more holes in the walls. By the way," John cocked his head in puzzlement, "why the pinkish hue to the cake? Cheesecakes are usually white."

"The recipe called for red cherries. We didn't have any. I thought it needed a splash of colour so I used…"

"Noooo, you didn't!" John gasped.

"What? You think I'd use blood?" The chemical mastermind shot John an annoyed frown. "You underestimate my brilliance in these matters, John. Not only would that be gross, it is scientifically impossible. Real blood oxidises and turns brown too quickly to be useful as a red food colorant."

"Right." John grumbled. His appetite for dessert was rapidly slipping away.

"If you're still curious, I used a few drops of harmless phenolphthaleine."

"Ok. Sherlock, I am delighted with your brilliant and amazing talents in the culinary department today. Really, I am proud of how you managed such an aesthetically pleasing work of art." He paused. "But….well, how can I put this?"

"Just the facts, John."

"Ok. Then truthfully, I just can't eat it. I know it's illogical, perfectly harmless substitutions and all. I just, well, I just can't."

Sherlock sat up with a smirk. "That's fine, John. I wasn't going to let you have it anyway."

"What?" John blinked.

"Mrs Hudson had threatened to clean the kitchen unless I gave my brother, Mycroft, a gift for his birthday. So, I made this. He likes food. It's perfect."

John was silent a moment. His conscience wavered on the brink of warning Mycroft. Finally, he smiled. "I think we should decorate it with a few of those margarita-toothpick umbrellas. You're right, it'll be a perfect birthday present. I'm sure he'll appreciate it."

~0~

**A/N: Astute readers will know why Dr John Watson struggled a moment with his conscience. Phenolphthaleine is the main ingredient in laxatives.**


	2. Chapter 2 - Mycroft's Revenge

**A/N: A follow up to a phenolphthalein-laden cheesecake, made by Sherlock for his brother's birthday.**

Mycroft cursed his impatience. He should have known better. He should have waited for the analysis to come back from the laboratory. It was a gift from his younger brother, Sherlock, after all. Why, oh why did he eat it? He asked himself that question multiple times, in fact many, many times. "Just you wait," he breathed every time he rushed urgently to the loo.

~221B~

Mycroft thumbed through his chemistry files stored in the recesses of his brain, flipping through the memorised data from years gone past, old lab experiments at University. Most had not seemed particularly relevant at the time, but perhaps now he could finally find a practical application to one of those bubbling concoctions he'd heated over the Bunsen burner, coughing over the fumes, swearing off a career in experimental chemical research.

This time Mycroft would be patient. His time would come. He never mentioned the cheesecake fiasco, just a sterile thank you card sent off to 221B Baker Steet. Like a lion that stalks, hidden in the tall grasses, the prey unaware, Mycroft waited – very patiently.

~221B~

"I need those case files on the cardboard box killer." Sherlock sat across the desk from him with a petulant frown. "The sooner the better."

"Tomorrow." Mycroft nodded, unperturbed.

"No, I _need_ them today." The dark haired detective stood up abruptly and began pacing the office.

Mycroft sighed. "A little practise in patience might do you a bit of good, you know."

"I don't want patience. I want those case files." Sherlock glared at his older brother.

"Fine. I'll see what I can do," he acquiesced. "But I can't make any promises." He raised a warning eyebrow as the agile detective hopped on and over furniture in his circuit round the room, almost knocking over the tea set on the small table.

"I'm sure you'll manage," Sherlock muttered, completing lap number ninety-nine while Mycroft made phone calls and arranged details.

"They'll be here in an hour," he pronounced at last. "Why don't you let me ring Anthea and have her bring up coffee, maybe some biscuits, while you wait?"

"Don't bother. You know how I am when I have a case." Sherlock stalked out of the office. "I'll be back."

Mycroft nodded. He'd known Sherlock for quite a while, his whole life in fact. In a few minutes, Anthea brought in a tray with coffee and biscuits. "Thank you," Mycroft murmured as he gazed absently at the tropical fish lazily swimming between the seaweed strands that floated in their aquarium situated in the corner of his office.

"Are they here yet?"

"The files, you mean?" Mycroft took a sip of coffee. "I told you, one hour. It's been 20 minutes."

"Feels like an hour," the frustrated detective flopped into one of the office chairs.

"You should practise your observational powers on clocks," Mycroft replied serenely. Coffee?"

"Black, two sugars."

Mycroft set the mug down next to his brother.

Sherlock huffed. "Ugh, horrible coffee. You sure you put sugar in this?

"Yes, I'm sure," Mycroft gave a noncommittal shrug. "Government cutbacks and budgetary constraints, hard to get a quality brew anymore."

"Ping." An incoming text on Sherlock's phone assuaged his impatience for a moment. "Do you have the files? Lestrade's headed to the warehouse. Are you coming? – J"

"Coming – S" he typed backed.

Just then a knock on the door signalled an incoming visitor. "File for Mr Holmes, sir."

"Thank you. You can put them on the desk here," Mycroft indicated.

Before the assistant had even closed the door, Sherlock pounced on the files and eagerly flipped through them. His gave an affirmative appraisal of the information and tucked the envelope under his arm. "Must dash, brother. Criminals to chase. Legwork. Nothing you'd be interested in." He smirked and strode out the door without a backward glance.

"Later," Mycroft turned and picked up the empty coffee mug. A small smile flitted across his face.

~221B~

That evening…

"John!" Sherlock's alarm brought the doctor rushing up the stairs wondering if a bugler had his partner in a death choke.

John found his friend peering into the toilet bowel. "I don't think…I mean, it's not supposed to be… er, blue?"

John breathed a sigh of relief. His flatmate was apparently alive and well and free of any death-seeking assailant. He rapidly took in the situation. Tall genius, distressed expression, and a strikingly blue-green colour in the toilet bowl. "What's not supposed to be blue, Sherlock?" he asked innocently.

"My urine."

John raised a surprised and suspicious eyebrow. "Your urine? Seriously, you've called me up to examine the colour of your urine?"

"It's blue, John. I swear. I just peed blue."

Sherlock took a slow shuddering deep breath. "Blue, one of the primary colours in the visible spectrum, the name being derived from the Middle English _blewe _which goes back to the Old French _bleu _thought to be of Germanic origin. Blue, the colour of copper sulphate. Blue, as in blue eyes resulting from the Rayleigh scattering of light in the stroma of melanin-deficient irises. Blue in blue laser diodes utilised in particle image velocimetry. Blue, oft associated with harmony, faithfulness, confidence and sometimes sadness. Blue, relating to the archaic tradition of designating an infant of the male gender. Blue, the colour commonly associated with the sky, sea, ice, and cold – not my urine, a sterile liquid by-product secreted by the kidneys in a process that rids the body of water-soluble chemical wastes." He paused in his mental gymnastics and examined the aquamarine liquid swirling in the bowl. "And, based on the peculiar hue, I'd say it's along the wavelength of 460-470 nanometres."

He looked up with expectant, wide eyes at his personal physician. "What kind of poison am I going to die from?"

John stepped closer and looked over Sherlock's shoulder. After a moment he shook his head. "Well, I have good news and bad news. The good news is that you're not going to die, Sherlock." He stepped back and crossed his arms.

"And the bad news?" Sherlock inquired anxiously.

"How long ago did you give that cheesecake to Mycroft?"

"Um, two weeks ago. But what's that got to do with the bad news?"

"You've been to see Mycroft today, have you not?"

"Yes?"

"Well, I'm not the world's only consulting detective but I'm going to deduce that Mycroft was not so forgiving of the cheesecake episode." John unsuccessfully tried to stifle his laughter, "I suspect your brother has just found his revenge."

"So, what now?" the blue-peeing detective inquired.

"Oh, you'll be fine. Probably be about twenty four hours to finish excreting it all." He shrugged.

"John?"

"Yes?"

"You are not allowed to tell anyone. I forbid you, not even Mrs Hudson, and especially not Lestrade!"

John smiled.

* * *

A/N: There were a couple clues that the astute chemistry student will be able to utilise to figure out how Mycroft turned Sherlock's urine blue.

For those who are not chemistry students, consider the words, "aquarium fish", "black coffee", and "aquamarine".

For those of you who are still lost, look up "methylthioninium chloride".


	3. Ch 3 - Mycroft's Revenge Part 2

**A/N: ****It really wasn't fair that only Sherlock suffered from Mycroft's revenge. John had been a silent accomplice in the cheesecake birthday present fiasco, after all. **Credit for this chapter belongs to Englishtutor and her poor husband who unwillingly served as the 'guinea pig' for this experiment. Apparently, according to his research, the red lasts longer than the burn. (Englishtutor's other half is fine now, btw, and has since seen the humour in it all).

* * *

John was still chuckling to himself when he traipsed down the steps and situated himself in his favourite chair, computer balanced on his lap. He hadn't _actually_ promised not to tell. He wondered what Mrs Hudson might say. Perhaps she would shake her head and exclaim sympathetically, "oh, that poor boy! I'll bake some of his favourite scones, those chocolate chip ones." Then again, she could cluck her tongue and murmur, "rather serves him right…after what he did to ruin my perfectly good recipe!" On a more practical note, Mrs Hudson could just say, "Oh dear! I hope he doesn't dribble blue all over the toilet seat."

John sat, the corners of his mouth twitching upward, considering the options. His blue eyes sparkled. He tapped in his password and waited for his screen to pop up. _Invalid password_. A frown clouded his face. "Sherlock!" His voice trailed up the stair accusingly.

"What, John?"

"Why did you change my password?"

"I didn't change your password, John. Why would I bother to change it? Your passwords are not a barrier in my utilisation of your computer."

John had to agree with Sherlock on that last point.

He tried several more times. Perhaps he had changed his password during one of those mandatory updates and forgotten? He tried several more of his usual codes. No luck. He groaned. "Sherlock, I can't unlock my computer." He thought a moment. An idea popped into his head. "I bet you won't be able to deduce this password so easily," he shouted back up to his flatmate.

The challenge had its desired effect. The genius, with more than a smidgen of arrogance, flounced down the stairs, dressing gown flapping behind, and grabbed John's laptop with an air of eager anticipation written in his keen eyes.

"Tiny brains…" he muttered to himself as he fell back into the nearest chair and tapped rapidly across the keypad_. Invalid password_. He typed again. _Invalid password. Please remember that passwords are case sensitive. Please try again_. Sherlock's eyes narrowed to daggers and he dared the computer to defy him again. Unlike people, computers are not intimidated by consulting detectives. Once again, the screen proclaimed, _Invalid password_.

"John, there is something wrong with your machine." He tossed it back to John as if the thing had developed some kind of deadly and contagious hemorrhagic fever.

Just then, John's mobile buzzed with an incoming text message: _Having difficulty logging into your computer_? – MH

John swore under his breath and rapidly tapped back: _Whatever you did to my computer, fix it! I am not amused_. – JW

_Don't be so impatient, doctor. I suspect your computer has merely caught a virus. It should be well in 24 hours_. - MH

_You did this. You fix it_. – JW

_Some balls, once set in motion, can't be stopped. Why not get yourself a cup of tea while you wait_? – MH

_%$^&*_ - JW

John put his computer to rest on the desk and stalked over to the kitchen. He put the kettle on to boil and rummaged around among the paraphernalia on the countertop, finally locating his favourite mug. "Ugh, Sherlock! Everything's dirty. Can't you even manage to wash a few dishes now and then?"

"Hmmm, yes, tea will be fine, John," Sherlock murmured, deliberately oblivious to John's accusations.

"Brothers," John grumbled and shook his head. He fished out another cup from the clutter and poured them both a steaming brew. Without a word, he set the one mug by his languid partner who was apparently worn out from his recent unsuccessful computer deductions.

Still not in the best of moods, John flipped on the telly. He sunk down into the cushioned chair and absently flipped through the channels. He rubbed his eyes as the fatigue of a long day crept up with him. "Ow! Bloody hell!" he yelped. His eyes burned like fire. Tears streamed down his cheeks. "What the F*?!"

"Something the matter?" The reposing figure on the sofa calmly inquired, his grey eyes slowly shifting to gaze in the general direction of the ruckus.

"Is something the matter? What do you think, genius? Yes, something's the matter! I rubbed something in my eyes and it hurts – hurts like hell - in case your observational skills are lacking tonight." John danced around the room, waving his arms blindly in front of him, finally ending up at the sink to try and rinse out his flaming orbs with cool water.

"You don't need to get so worked up. Clearly your eyes are not on fire."

"Oh, just shut up," John grimaced, " you're clearly lacking in the sympathy department tonight."

"Well, I don't recall you being particularly compassionate yourself earlier tonight when I needed your help on a matter of blue kidney excretions," Sherlock remarked.

"Oh, just go find my flourescein eye drops, Sherlock? I need to see if whatever I rubbed into my eye caused a corneal ulceration."

"Where?"

"My medical bag upstairs, by the dresser."

"Haven't had the chance to observe one of those in years, must make a note to ask Molly for more eyes," Sherlock's voice trailed off as he bounded up the steps to fetch the dye with eager anticipation.

John heard his partner crashing around in his search upstairs when suddenly a blood-curdling scream erupted from the upper rooms. "Jooohhhhnnnnn!"

Patting his face dry, John dashed up the stairs once again. "I told you, Sherlock, your pee is going to be blue for a - " He stopped mid sentence.

Eyes red. Tears flowing down his face. Sherlock winced back at John. "You're right, it burns." He blinked painfully and stumbled toward the bathroom sink. "Something on our hands. When we rubbed our eyes…" The splashing water drowned out the rest of his deduction.

Some time later, after much yelping and swearing, two red-eyed, face-dripping companions with thoroughly scrubbed hands, collapsed onto the sofa.

"Experiments on dead people's eyes are much less tedious." The tall detective stated decisively.

"Better your eyeballs from Bart's than mine," agreed John. "Thankfully, neither of us had any corneal damage."

"My eyes feel better."

"Yea, mine too."

Sherlock glanced over at the mirror by the hearth. "They're still rather red."

"I suspect they'll be that way for a while," John sighed wearily.

"You think Mycroft – ?"

"I'm sure Mycroft had something to do with this," John finished emphatically. "I don't have to be a consulting detective to know your brother is exacting his revenge. I should have known, I suppose."

Sherlock's mobile beeped: _24 hours, brother. It's only fair, after all_. – MH

John's mobile buzzed with its own incoming message: _Your complicit participation in the cheesecake affair was not forgotten, John. I'd suggest you wash your teacups with much soap and water_. – MH

John groaned. He looked over at his dark-haired, damp, bedraggled friend, now with blood-shot eyes accenting his fair skin. "You're a mess," he stated blandly. "Red eyes. Blue pee. Patriotic, actually." Now that the pain had dissipated, John's humour was beginning to return.

"I'd rather not be patriotic in this manner, John."

"Yea, I agree. And, anyway, we're missing the colour white."

"Oh, I'm not so sure. We could always add my brother's white arse to the collection."

Each man was silent for a few moments, contemplating this thought. John looked over at Sherlock. Sherlock snuck a glance over at his doctor who appeared to have imbibed more than a fair share of alcohol with his flaming eyes. He cracked a half smile. John noticed and tried to stifle his own mirth as he remembered his blue-peeing partner's shocked expression earlier. Suddenly, neither could hold it in any longer. They both burst out in peals of laughter. Tears streamed out of their eyes.

John's phone buzzed again. _What's so funny_? – MH

In between bouts of shaking laughter, John managed to text back: _Red, white, and blue_. – JW

* * *

A/N: I suspect readers have figured out the chemical Mycroft utilised in his revenge. If not, look up "_Capsicum annuum"_


End file.
